The present invention relates to a liquid ejecting head for ejecting desired liquid using generation of a bubble by applying thermal energy to the liquid, a head cartridge using the liquid ejecting head, a liquid ejecting device using the same, a manufacturing method for the liquid ejecting head, a liquid ejecting method, a recording method, and a print provided using the liquid ejecting method. It further relates to an ink jet head kit containing the liquid ejection head.
More particularly, it relates to a liquid ejecting head having a movable member movable by generation of a bubble, and a head cartridge using the liquid ejecting head, and liquid ejecting device using the same. It further relates to a liquid ejecting method and recording method for ejection the liquid by moving the movable member using the generation of the bubble.
The present invention is applicable to equipment such as a printer, a copying machine, a facsimile machine having a communication system, a word processor having a printer portion or the like, and an industrial recording device combined with various processing device or processing devices, in which the recording is effected on a recording material such as paper, thread, fiber, textile, leather, metal, plastic resin material, glass, wood, ceramic and so on.
In this specification, xe2x80x9crecordingxe2x80x9d means not only forming an image of letter, figure or the like having specific meanings, but also includes forming an image of a pattern not having a specific meaning.
An ink jet recording method of so-called bubble jet type is known in which an instantaneous state change resulting in an instantaneous volume change (bubble generation) is caused by application of energy such as heat to the ink, so as to eject the ink through the ejection outlet by the force resulted from the state change by which the ink is ejected to and deposited on the recording material to form an image formation. As disclosed in U.S. Pat. No. 4,723,129, a recording device using the bubble jet recording method comprises an ejection outlet for ejecting the ink, an ink flow path in fluid communication with the ejection outlet, and an electrothermal transducer as energy generating means disposed in the ink flow path.
With such a recording method is advantageous in that, a high quality image, can be recorded at high speed and with low noise, and a plurality of such ejection outlets can be posited at high density, and therefore, small size recording apparatus capable of providing a high resolution can be provided, and color images can be easily formed. Therefore, the bubble jet recording method is now widely used in printers, copying machines, facsimile machines or another office equipment, and for industrial systems such as textile printing device or the like.
With the increase of the wide needs for the bubble jet technique, various demands are imposed thereon, recently.
For example, an improvement in energy use efficiency is demanded. To meet the demand, the optimization of the heat generating element such as adjustment of the thickness of the protecting film is investigated. This method is effective in that a propagation efficiency of the generated heat to the liquid is improved.
In order to provide high image quality images, driving conditions have been proposed by which the ink ejection speed is increased, and/or the bubble generation is stabilized to accomplish better ink ejection. As another example, from the standpoint of increasing the recording speed, flow passage configuration improvements have been proposed by which the speed of liquid filling (refilling) into the liquid flow path is increased.
Japanese Laid Open Patent Application No. SHO-63-199972 propose flow passage structures as disclosed in FIG. 1, (a) and (b), for example.
The liquid path or passage structure of a manufacturing method therefor are proposed from the standpoint of the back wave toward the liquid chamber. This back wave is considered as energy loss since it does not contribute to the liquid ejection. It proposes a valve 10 disposed upstream of the heat generating element 2 with respect to the direction of general flow of the liquid, and is mounted on the ceiling of the passage. It takes an initial position wherein it extends along the ceiling. Upon bubble generation, it takes the position wherein it extends downwardly, thus suppressing a part of the back wave by the valve 10. When the valve is generated in the path 3, the suppression of the back wave is not practically significant. The back wave is not directly contributable to the ejection of the liquid. Upon the back wave occurs in the path, the pressure for directly ejecting the liquid already makes the liquid ejectable from the passage.
On the other hand, in the bubble jet recording method, the heating is repeated with the heat generating element contacted with the ink, and therefore, a burnt material is deposited on the surface of the heat generating element due to kogation of the ink. However, the amount of the deposition may be large depending on the materials of the ink. If this occurs, the ink ejection becomes unstable. Additionally, even when the liquid to be ejected is the one easily deteriorated by heat or even when the liquid is the one with which the bubble generation is not sufficient, the liquid is desired to be ejected in good order without property change.
Japanese Laid Open Patent Application No. SHO-61-69467, Japanese Laid Open Patent Application No. SHO-55-81172 and U.S. Pat. No. 4,480.259 disclose that different liquids are used for the liquid generating the bubble by the heat (bubble generating liquid) and for the liquid to be ejected (ejection liquid). In these publications, the ink as the ejection liquid and the bubble generation liquid are completely separated by a flexible film of silicone rubber or the like so as to prevent direct contact of the ejection liquid to the heat generating element while propagating the pressure resulting from the bubble generation of the bubble generation liquid to the ejection liquid by the deformation of the flexible film. The prevention of the deposition of the material on the surface of the heat generating element and the increase of the selection latitude of the ejection liquid are accomplished, by such a structure.
However, with this structure in which the ejection liquid and the bubble generation liquid are completely separated, the pressure by the bubble generation is propagated to the ejection liquid through the expansion-contraction deformation of the flexible film, and therefore, the pressure is absorbed by the flexible film to a quite high degree. In addition, the deformation of the flexible film is not so large, and therefore, the energy use efficiency and the ejection force are deteriorated although the some effect is provided by the provision between the ejection liquid and the bubble generation liquid.
Accordingly, it is a principal object of the present invention to provide a structure for a movable member in a liquid ejection using the movable member.
It is another object of the present invention to provide a liquid ejection principle with which the generated bubble is controlled in a novel manner.
It is a further object of the present invention to provide a liquid ejecting method, liquid ejecting head and so on wherein heat accumulation in the liquid on the heat generating element is significantly reduced, and the residual bubble on the heat generating element is reduced, while improving the ejection efficiency and the ejection pressure.
It is a further object of the present invention to provide a liquid ejecting head and so on wherein inertia force in a direction against liquid supply direction due to back wave is suppressed, and simultaneously, a degree of retraction of a meniscus is reduction by a valve function of a movable member by which the refilling frequency is increased, thus permitting high speed printing.
It is a further object of the present invention to provide a liquid ejecting head and so on wherein deposition of residual material on the heat generating element is reduced, and the range of the usable liquid is widened, and in addition, the ejection efficiency and the ejection force are significantly increased.
It is a further object of the present invention to provide a liquid ejection method and a liquid ejection head, wherein excessive vibration is regulated within a desired range, and the durability of the movable member is improved.
It is a further object of the present invention to provide a liquid ejecting method, a liquid ejecting head and so on, wherein the choice of the liquid to be ejected is made greater.
It is a further object of the present invention to provide a head kit for permitting easy refuse of the liquid ejecting head.
According to an aspect of the present invention, there is provided a liquid ejecting head for ejecting liquid by generation of bubble, comprising: an ejection outlet for ejecting the liquid; a liquid path in fluid communication with the ejection outlet; a bubble generation region for generating the bubble in the liquid; a movable member having a fulcrum and a free end and disposed faced to the bubble generation region; wherein the movable member moves from the first position to the second position by pressure produced by the generation of the bubble, and a resistance against movement of the movable member, is smaller adjacent the free end than adjacent the fulcrum.
According to another aspect of the present invention, there is provided a liquid ejecting head for ejecting liquid by generation of bubble, comprising: an ejection outlet for ejecting the liquid; a liquid path in fluid communication with the ejection outlet; a bubble generation region for generating the bubble in the liquid; a movable member having a fulcrum and a free end and disposed faced to the bubble generation region; wherein the movable member moves from the first position to the second position by pressure produced by the generation of the bubble, and a height of the flow path is higher above the free end than above the fulcrum end.
According to a further aspect of the present invention, there is provided a liquid ejecting head for ejecting liquid by generation of bubble, comprising: an ejection outlet for ejecting the liquid; a liquid path in fluid communication with the ejection outlet; a bubble generation region for generating the bubble in the liquid; a movable member having a fulcrum and a free end and disposed faced to the bubble generation region; wherein the movable member moves from the first position to the second position by pressure produced by the generation of the bubble, and a height of the flow path is lower at least in a portion between a position of the free end and a position of the fulcrum than at the position of the free end.
According to a further aspect of the present invention, there is provided a liquid ejecting head for ejecting liquid by generation of bubble, comprising: a first liquid flow path in fluid communication with an election outlet; a second liquid flow path having bubble generation region for generating the bubble in the liquid by applying heat to the liquid.; a movable member disposed between the first liquid flow path and the bubble generation region and having a free end adjacent the ejection outlet, wherein the free end of the movable member is displaced into the first liquid flow path by pressure produced by the generation of the bubble, thus guiding the pressure toward the ejection outlet of the first liquid flow path by the movement of the movable member to eject the liquid, wherein a height of the flow path is higher above the free end than above the fulcrum end.
According to a further aspect of the present invention, there is provided a liquid ejecting head for ejecting liquid by generation of bubble, comprising: a first liquid flow path in fluid communication with an ejection outlet; a second liquid flow path having bubble generation region for generating the bubble in the liquid by applying heat to the liquid; a movable member disposed between the first liquid flow path and the bubble generation region and having a free end adjacent the ejection outlet, wherein the free end of the movable member is displaced into the first liquid flow path by pressure produced by the generation of the bubble, thus guiding the pressure toward the ejection outlet of the first liquid flow path by the movement of the movable member to eject the liquid, wherein a height of the flow path is lower at least in a portion between a position of the free end and a position of the fulcrum than at the position of the free end.
According to a further aspect of the present invention, there is provided a liquid ejecting method for ejecting liquid by generation of a bubble, comprising: preparing a head comprising an election outlet for ejecting the liquid, a bubble generation region for generating the bubble in the liquid, a movable member having a free end and a fulcrum and disposed faced to the bubble generation region; displacing the movable member by pressure produced by the generation of the bubble in the bubble generating portion, wherein a resistance against movement of the movable member, is smaller adjacent the free end than adjacent the fulcrum.
According to a further aspect of the present invention, there is provided a liquid ejecting method for ejecting liquid by generation of a bubble, comprising: preparing a head including a first liquid flow oath in fluid communication with a liquid ejection outlet, a second liquid flow path having a bubble generation region and a movable member disposed between the first liquid flow path and the bubble generation region and having a free end adjacent the election outlet side; and generating a bubble in the bubble generation region to displace the free end of the movable member into the first liquid flow path by pressure produced by the generation of the bubble, thus guiding the pressure toward the ejection outlet of the first liquid flow path by the movement of the movable member to eject the liquid, wherein a resistance against movement of the movable member, is smaller adjacent the free end than adjacent the fulcrum.
According to a further aspect of the present invention, there is provided a liquid ejection recording method for ejecting recording liquid by generation of a bubble to effect recording, comprising: preparing a head comprising an ejection outlet for ejecting the recording liquid, a bubble generation region for generating the bubble in the liquid, a movable member having a free end and a fulcrum and disposed faced to the bubble generation region; displacing the movable member by pressure produced by the generation of the bubble in the bubble generating portion, wherein a resistance the liquid, against movement of the movable member, is smaller adjacent the free end than adjacent the fulcrum.
According to a further aspect of the present invention there is provided a head cartridge comprising: a liquid ejecting head as defined above; and a liquid container for containing the liquid to be supplied to the liquid ejecting head.
According to a further aspect of the present invention there is provided a liquid ejecting apparatus for ejecting recording liquid by generation of a bubble, comprising: a liquid ejecting head as defined above; and driving signal supply means for supplying a driving signal for ejecting the liquid through the liquid ejecting head.
According to a further aspect of the present invention there is provided a liquid ejecting apparatus for ejecting recording liquid by generation of a bubble, comprising: a liquid ejecting head as defined above; and recording material transporting means for feeding a recording material for receiving the liquid ejected from the liquid ejecting head.
According to a further aspect of the present invention there is provided a recording system comprising: a liquid ejecting apparatus as defined above; and a pre-processing or post-processing means for promoting fixing of the liquid on the recording material after the recording.
According to a further aspect of the present invention there is provided a head kit comprising: a liquid ejecting head as defined above; and a liquid container containing the liquid to be supplied to the liquid ejecting head.
According to a further aspect of the present invention there is provided a head kit comprising: a liquid ejecting head as defined above; a liquid container for containing the liquid to be supplied to the liquid ejecting head; and liquid filling means for filling the liquid into the liquid container.
According to a further aspect of the present invention there is provided a recorded material characterized by being recorded by ejected ink through a liquid ejection recording method as defined above.
According to the present invention, the object of which is to provide the structure described above, it was possible to prevent the free end of the moving member from moving into the bubble generation region (toward the heat generating member) far beyond the first position; therefore, the durability of the moving member could be improved.
In this embodiment, the height of liquid flow path is higher right above the free end than right above the fulcrum of the movable member, or it is lower at least a part between a position faced to the free end and a position faced to the fulcrum than at the position faced to the free end. By this, the resistance, by the liquid itself or by the structure of the flow passage, against the motion of the movable member is smaller adjacent the free end of the movable member than adjacent the fulcrum, by which the ejection state of the liquid is stabilized, and the ejection force can be increased.
With the liquid ejecting method and the head using the novel ejection principle, a synergistic effect is provided by the generated bubble and the movable member moved thereby so that the liquid adjacent the ejection outlet can be ejection with high efficiency, and therefore, the ejection efficiency is improved. For example, in the most desirable type of the present invention, the ejection efficiency is increased even to twice the conventional one.
In another aspect of the present invention, even if the printing operation is started after the recording head is left in a low temperature or low humidity condition for a long term, the ejection failure can be avoided. Even if the ejection failure occurs, the normal operation is recovered by a small scale recovery process including a preliminary ejection and sucking recovery.
In an aspect of improving the refilling property, the responsivity, the stabilized growth of the bubble and stabilization of the liquid droplet during the continuous ejections are accomplished, thus permitting high speed recording.
In this specification, xe2x80x9cupstreamxe2x80x9d and xe2x80x9cdownstreamxe2x80x9d are defined with respect to a general liquid flow from a liquid supply source to the ejection outlet through the bubble generation region (movable member).
As regards the bubble per se, the xe2x80x9cdownstreamxe2x80x9d is defined as toward the ejection outlet side of the bubble which directly function to eject the liquid droplet. More particularly, it generally means a downstream from the center of the bubble with respect to the direction of the general liquid flow, or a downstream from the center of the area of the heat generating element with respect to the same.
In this specification, xe2x80x9csubstantially sealedxe2x80x9d generally means a sealed state in such a degree that when the bubble grows, the bubble does not escape through a gap (slit) around the movable member before motion of the movable member.
In this specification, xe2x80x9cseparation wallxe2x80x9d may mean a wall (which may include the movable member) interposed to separate the region in direct fluid communication with the ejection outlet from the bubble generation region, and more specifically means a wall separating the flow path including the bubble generation region from the liquid flow path in direct fluid communication with the ejection outlet, thus preventing mixture of the liquids in the liquid flow paths.
The free end portion or region of the movable member may mean the free end edge at the downstream side of the movable member or may mean the free end edge and the lateral edges adjacent the free end.
The resistance edgiest the motion of the movable member means the resistance due to the liquid itself or the structure of the liquid passage when the movable member moves away from the bubble generation region by the generation of the bubble. The resistance may be reduced by providing a resistance inclination, using a resistance by physical stopper, using a resistance of virtual-stopper with the use of fluid. The resistance is called herein after resistance or flow resistance.
These and other objects, features and advantages of the present invention will become more apparent upon a consideration of the following description of the preferred embodiments of the present invention taken in conjunction with the accompanying drawings.